A store-bought bun shaper looks like this:
And with one you can do hairstyles like this:
So, let's get to it.
Step 1: Cut toe off of sock and a section of nylon (with both ends cut off) approximately 3" long.
Step 2: Roll the sock all the way down to form a donut.
Step 4: Insert tube of nylon into the center of the donut.
Step 5: Wrap the nylon around the donut so that the two cut edges touch around the inside.
Step 6: Whipstitch the raw edges of the nylon together.
Step 7: Put the seam on the inside of the donut (so the entire outer section is smooth) and you're done!